Milling machine



April 23, 1940. c. H. NEL SON MILLING MACHINE Original Filed Nov. 2, 1936 I I I I I I INVENTOR. Mm

ATTofi'N Y an m xlv Patented Apr.-.23, 1940 a "Cary I-lollis Nelson, Altadena, Calif.

1 ippnatatimesttrz, 1936 Serial No. 108,716 '5 'ltene'wed August 7, I

reclaims. (01. 90-439) This invention relates. to and has for an object I thereof theprovision of a milling machine which is especially constructed. for cutting helical guide grooves or slots in, the float guide. members of 5 float operated liquid level gauges for liquid storage tanks, especially horizontal cylindrical tanks.

In the construction .oj such gauges for horizontal cylindrical tanks wherein' the volume is not. directly proportionalpto the levels therein, I and wherein the galige,..comprises a float rotated by a hellcally groovedorslotted guide member responsive to changes' inj the levelof theliquid in the tank,and the float in turning moves an indicator .over an. evenly'graduated dial,.it is 1; necessary that the'pitch of the grooves 013810125 be accurately varied according to the varying re-. lationship of the 'volume to the diameter of the tank and to tanksof different sizes.- 1

' Heretofore, thefp rovision ofsflch groo es or slots of proper and accurate, formv hasflbeen a diflicult, painstaking and costly operation for dials having equally spacedgr'aduations, or has required they use. of dials having various spaced graduations' which has necessitated especially- 39 operated to. cut,he'lical, slots in thedesired pitch in the fioatiguide'members for suc'hliguid level A further object isto provide afmachine of the character describedwhich may be readily manipulated tocut the grooves'or slots .joi-yarying pitch to suit tanks or varying diameter and capacity,

while using Standardized dials having Euniformly spaced graduations,

More. specifically, this invention contemplates a, a machine which will cut or're'p'roduce. a re ularly distorted. helical slot or guidewhich may have an 1 equal and opposite component, if desired, wherein the degrees of a radial advanceperlunit of length areas inside the perimeter andbetween parallel chords of that circle, saidlchords being spaced the same as said unitsof length and at right angles to said helix centehline. Slots or-guides of .-these 5o characteristics with the float willprovide for the advantages hereinbefore-noted in a particularly.

efiicacious manner l Moreover, it is anoth along the helix center line, this line being the diameter of a'circle, are directly proportional to the a I I the template or as otherwise desired.

r; objectof this invention I to provide a machine wherein a:template havinga mm-ev o a v i1e 'ttaa.srre late distorted,

PAT NT .oF-Flcs helical form is rotate'dfat a given speed bydrive means, which is a laterally movable member e'n-' gaging in said groove, and the template, through a .variable, speed drive connection with work chucks, will rotate the work through some irac. tionor multiple and fraction of the total degrees of revolution .of the template, simultaneou'slywith the rotation. of the template. Furthermore, the means .for driving the template operates through a variable speed connection for the lateral movement of a cutting tool, through any traction of the-length of the machine, greater ,or less than the length of the template, while the template. groove engaging vmember'movesthe full length oi!v said groove. By these means themachine may be operated to out helical slots or grooves in given varying lengths and: degrees of revolution while maintaining a constant distortion in all cases.v

Other objectsmay appear as thedescription progresses."

I have shown a preferred form of my IDVBIItIOII- J Y '30.. ,Fig. 3 isa'sectional view taken on the plane or Fig. 4 is a diagram of the given curve voflthe template and typical variational curveswhich are provided with the variable pitch of tthegrooves or slots; a l; s

Figs. 5 a 'd 6 are fragmentary top plan views of two specimens of work having slots following the curves shown in the upper and lower diagram linesof Fig. 4. With particular reference to the drawing, the embodiment of the invention shownjtherein. com.- prises a frame I and a motor 2 which, through reduction gearing 3, operates a driving shaft 4!. This shaft has a screw threaded portion 5 vwhichactuates a driving member 6 threadedly engaged therewith; A cylindrical template l having a 'helical pattern groove'll is rotated by the member E engaging with said groove. This template through variable speed transmission means 9 rotates work chucks l0 and l l at the same speed as Through l It will be noted that the variable speed means 9 is adapted to rotate at various speeds, a shaft M which, through gears I5, l6 and I1, rotates a shaft 1 8. The shaft I8 drives the work chucks I0 and I! through gears l9 and 20 and 2| and 22 respectively. Gear 2| is splined on said. shaft, whereby the chuck II, which is suitably laterally adjustably mounted on the machine, will be driven in any adjusted position thereof. Chuck l I is constructed to slidably yet rotatably receive the rod or tube A, which is to be helically grooved or slotted, and thereby provides for cutting grooves or slots in rods or tubes of greater or lesser length than the helical pattern guide.

, The variable speed device I 2 is arranged to rotate at various speeds a feed screw 24 which is threadedly engaged with and thereby moves the 1 tool chuck l3 laterally at whatever speed desired,

depending on the nature of the helical groove to ting of free and accurate movements of the parts 6, II and I3 v It .'.will benoted thatthe tool chuck l3 includes a motor 33 adapted to rotate a tool holder 34 in which a groove or slot cutting, tool 35 is held so as to engage the work, as shown in Fig. 3.

The variable speed transmission devices 9 and l 2 may beof any conventional form provided that upon manipulation of the, handles 36 and 31 thereof, said devices will operate the work and the tool chucks at various speeds as desired.

In the operation of the machine, for example, to cut a helical slot in the tube A, as shown in Fig. l, the operator} having first determined the degree of revolution and the length along the tube centerline of the helical slot to be cut in said tube,

in consideration of thediameter and capacity of the particular horizontal cylindrical storage tanks for which the-tube is to be prepared, now

sets the tube in place and adjusts the variable speed devices 9 and I2 before starting the motors land 33. It willbe noted that the helical pattern groove 8 of the template I has a regularly distorted helical curve of a given length with a able speed devices 9 and I2.

If it is desired, for example, to produce a slot in the tube A identical with the pattern groove 8 of the template I, the transmission 9 is manipulated to rotate the tube at the same speed as the template'and the. transmission means I2 is set to feedthe' cutter at a lateral speed equal to movement of the drive means 6 in the pattern groove 8. A slotthus cut will have the curve indicated at B in Fig. 4.

It will be seen that by various speed settings for rotation of the tube or work to have a groove or slot cut-therein, and likewise by various speed settings for the lateral movement of the cutter,

both relative to the speed or rotation of the template and the speed of movement of the drive means 6 in the template groove 8, I may reproduce helical slots or grooves of various length and revolution to suit, tanks of various diameters and capacities. v will provide for readily and accurately cutting grooves or slots of given varying lengths and 'de-.

may form grooves or slots having the curves as indicated at Cand D in Fig.4, or may otherwise yet similarly vary the template curve.

In terms of volume, the machine of this invention may be said to provide a regularly dis+ torted helical slot,.,which may or may not have an equal and opposite'component, wherein the degrees ofradial advance per unit of length along In other words, the machine hereof its (the helix) center line (this center line being the true diameter of a cylinder), aredirectly proportional to'the volumes insidethe cylinder'and between parallel planes dissectingthe cylinder,-

said planes spaced the same asxsaid units of length, and being perpendicular, to saidheli'xf In Figs. 5 and 6 are shown two samples E and F of work having the slots *following the curves,

center line.

shown in lines ,Cand D, respectively, of ,Fi-g. 4.

While thepresent embodiment is particularly designed for. cutting grooves or slots it is to be;

understood that anymodificationof this embodiment which willcut a rib' or some other form of helicalguide corresponding in shape andfunction to the groove or. slot herein described, will be within thescope of this invention.

It should be notedthat any Suitable means may be employed forreturning the members'fi and, I3 ,7

to normal position. Iii desired, this can beaccomplished by reversingfthe motor 2, while the cutting tool is disengaged from the'work.

What I claim is; I

1. In amilling machina a rotary template, ro-

tary work holding means, means for rotating said template including a driving shaft, a variable speed driving connection between said template and said work holding means, a cutting tool,

means for advancing said tool axially 'of,the work, including a] rotary shaft, and. a variable speed driving connection between said shafts.

2. In a milling machine, a rotary template, ro tary work holding means, means for rotating said template including adriving shaft and a member slidably engaging said template, a variable speed driving connection between said template and said work holding fmeans, a cutting tool, means for advancing said tool axiallypf the work, in eluding a rotary shaft, and a variable speed drive,

ing. connection between said shafts} 3. In a milling machine, a rotary template having'a peripheralhelical groove, rotary work holding means, means for rotating said template in-' cluding a driving shaft anda slida'ble member tary shaft, and a variable speed" driving connec tion between said shafts.

4. In a milling machinaa rotary template having a helical guide therein, a member engaging in said guide, a feed screw threadedly engaged with and for moving said memberaxially of said template, a rotary work holding means, a variable; I

speed driving connection between said template and said work holding means, a cuttingtool,

at: a I

-' means for rotating said template,- including: a-

ziieaees nectionibetween said fe'ed screws 5, In a millin -machine; 7 a rotarytemplate;

plate, arotarywbrk' h'oldin means,means"driveri axiallyof the workand a -variable speed drive by the template for rotatingsaid work holdin-gmeans, a cutting tool, means for mtvmgsam tool connection between last "named means and said v template rotating means for varying the speed of movement of the cutting tool.

template, including a driving shaft, a variable speed driving connection between said shafts, a

manually operable control member for said variable speed means, a variable speed driving con-- nection between said template and said rotary Work .holder and manually operable control means for said last named variable speed connection.

7. In a milling machine, a rotary template, a rotary work holder, means for rotating said template, including a driving shaft, a drive connection between said template and said work holder including manually operable means for effecting various speed settings of said drive means, a cutting tool, means for advancingsaid tool axially of the work including a rotary shaft, and a drive connection between said shafts including various speed settings and manually operable means for changing said settings.

8. In a milling machine, a rotary template having a helical guide groove therein, a drive member engaging in said groove, a feed screw threadedly engaged with and moving said drive member axially of said template, a rotary work holder, means driven by said template for rotating said work holder and including a change speed device and manually operable means for setting said device for operation at various speeds, a cutting tool, means for advancing said" tool axially of the work, including a rotary feed screw, a drive connection between said feed screws, and a manually operable change speed device between said feed screws.

9. In a milling machine, a rotary'template hav ing a regularly distorted'helical guide element wherein the degrees of radial advance per unit of length along the helix center line, this line being thetrue diameter of a cylinder, are directly proportional to the volumes inside the cylinder and between parallel planes bisecting the cylincler, said planes being spaced the same as said units of'length and being perpendicular to said helix center line, a rotary work holder, means" for rotating said template, including a driving shaft, adrive connection between said template and said work holder'including manually oper-' able means for effecting various speed settings of said drive means, a cutting tool, means for advancing said tool axially of the work including a rotary shaft, and a drive connection between said shafts including various speed settings and manually operable means for changing said settings. i'

10. In a milling machine, a rotarytemplate having a helical guide groove wherein the dedrive member engaging in said? groove; a feed speed device and) manual-n operable ni-eans' 'for' to the 5 volume inside: the cylifidr ana -betwee parallel planes b ecti'ng the ;-cylindi=;r said planes? being spaced the same as said units of length and being perpendicular 'to said helix --ceinter line; a

screw- -threadedl yengaged with and moving said drive me ber 'axia'lly 'of said template} a: otawork holder, means driven' oysaid template for rotating said -work"hol 'der and including a cnange setting said device for operation at various speeds, a cutting tool, means for advancing said tool axially of the work, including a rotary feed screw, a drive connection between said feed screws, and a manually operable change speed device between said feed screws. I

11. In a milling machine, a rotarytemplate having a regularly distorted helical guide element wherein the degrees of radial advance per unit of length along the 'helix center line, the center 20 line being the diameter of a circle, are directly proportional to the areas inside of the perimeter and between parallel chords of that circle, said chords spaced the same as said units of length and at right angles to said helix center line, a rotary work holder, means for rotating said template, including a driving shaft, a drive connection between said templateand said work holder including manually operable means, for effecting various speed settings of said. drive means, a, cutting tool, means for advancing said tool axially of the work inducing a rotary shaft, and a drive connection between said shafts includingvarious speed settings and manually op-' erable means for changing said settings.

12. In a milling machine, a rotary template having a helical guide groove wherein the degrees of radial advance per unit of length along the helix center line, the center line being the diameter of .a circle, are directly proportional to the areas inside of the perimeter and between parallel chords of that circle, said chords spaced thesame assaid units of length and at right angles to said helix center line, a drive member engaging in said groove, a feed screw threadedly engaged with and moving said drive member axially of said template, a rotary work holder,,means driven by i said template for rotating said work holder and including a change speed device and manually operable'means for setting said device for oper-'-- ation at various speeds, a cutting tool, meansffor advancing said tool axially of the work, including a rotaryfeed screw, a drive connection between said feed screws, and a manually operable change speed device between. said feed screws.

13. In a, milling machine, means for predetermining th epath of a tool in relation tothe work, a drive member therefor, a rotary work holder, a drive connection between said means and said workholder including a change speed device, a manually operable means for setting said device for operating said work holder at various speeds, a tool, means for moving 'saidgtool axially of the work simultaneously with the operation of said termined degrees of radial advance as per said 70 a path. v 14. In a milling machine, means for predetermining the path of a tool in relation to the work, a drive member therefor, a rotary work holder,

a drive connection between said means and said 75 Work holder including a; change-speed device; a manually operable means for setting said device for operating said work holder at various speeds,, a tool, means for moving said tool axially of the h work simultaneously with'the operation of said termined degrees of radial advance as per said path, wherein the degrees of radial advance per. unit of length along the helix center line, this; line being the true diameter of a cylinder, are

proportional, to the volumes insidethe cylinder and between parallel planes 'bisecting the cylinder,-said planes being spaced the same as said units of length and being perpendicular to said helix center line.

CARY HOLLIS NELSON." 10 i 

